U.S. patent number 5,539,811 [Application Number 08/226,591] was granted by the patent office on 1996-07-23 for visual communication terminal apparatus for performing multiplex transmission of image and audio signals.
This patent grant is currently assigned to Matsushita Electric Industrial Co., Ltd.. Invention is credited to Junji Nakamura, Toshihiro Nishimura.
United States Patent |
5,539,811 |
Nakamura , et al. |
July 23, 1996 |
Visual communication terminal apparatus for performing multiplex
transmission of image and audio signals
Abstract
A visual communication is performed between a calling party and
a called party through a plurality of channels. After the parties
are connected through a first channel, an available telephone
number of a second channel stored in a BAS control portion is read
to a TNI control portion on each of the parties, and the TNI
control portions of the parties exchange the available telephone
numbers. Thereafter, when an incoming call having a telephone
number is received through the second channel by a call control
processing portion of the called party, the telephone number of the
call is compared with the available telephone number of the second
channel by an ICJ portion. To perform correct visual communication
between parties, in cases where the telephone number of the call
agrees with the available telephone number, the call is established
by the call control processing portion, and image and audio signals
are transmitted from the calling party to the called party through
codec portions, multiplexing/demultiplexing portions and the first
and second channels to perform a visual communication. In contrast,
in cases where the telephone number of the call does not agree with
the available telephone number, the second channel is released.
Inventors: |
Nakamura; Junji (Fukuoka,
JP), Nishimura; Toshihiro (Fukuoka, JP) |
Assignee: |
Matsushita Electric Industrial Co.,
Ltd. (Osaka, JP)
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Family
ID: |
13882481 |
Appl.
No.: |
08/226,591 |
Filed: |
April 12, 1994 |
Foreign Application Priority Data
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Apr 13, 1993 [JP] |
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5-086282 |
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Current U.S.
Class: |
379/93.14;
348/14.01; 348/E7.081; 348/E7.082; 370/535; 379/93.19 |
Current CPC
Class: |
H04N
7/147 (20130101); H04N 7/148 (20130101); H04Q
11/0428 (20130101); H04Q 2213/13034 (20130101); H04Q
2213/1307 (20130101); H04Q 2213/13097 (20130101); H04Q
2213/13204 (20130101); H04Q 2213/13208 (20130101); H04Q
2213/13209 (20130101); H04Q 2213/13216 (20130101); H04Q
2213/13292 (20130101); H04Q 2213/13337 (20130101); H04Q
2213/13367 (20130101) |
Current International
Class: |
H04Q
11/04 (20060101); H04N 7/14 (20060101); H04M
011/00 (); H04N 007/12 () |
Field of
Search: |
;379/93,94,96-100
;348/14-17 ;370/110.1,94.1 |
References Cited
[Referenced By]
U.S. Patent Documents
Foreign Patent Documents
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496562 |
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Mar 1992 |
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JP |
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4310055 |
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Nov 1992 |
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JP |
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548755 |
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Feb 1993 |
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JP |
|
Primary Examiner: Chan; Wing F.
Attorney, Agent or Firm: Lowe, Price, LeBlanc &
Becker
Claims
What is claimed is:
1. A visual communication terminal apparatus for communicating
between a first calling party and a called party connected through
a first channel, comprising at each called and calling party:
network interface means for transmitting at a first calling party,
to the called party through the first channel, a piece of
particular identifying information of a second channel differing
from the first channel;
for receiving, at the called party, the piece of particular
identifying information of the second channel transmitted from the
first calling party through the first channel;
for transmitting, at the first calling party or at a second calling
party, a call to the called party through the second channel;
and
for receiving, at the called party, the call transmitted from the
first calling party or from the second calling party through the
second channel;
identifying information controlling means for preparing, at the
first calling party, the piece of particular identifying
information transmitted to the called party through the network
interface means of the first calling party and the first
channel;
for preparing, at the second calling party, a piece of general
identifying information of the second channel for transmission to
the called party through the network interface means of the second
calling party; and
for storing, at the called party, the piece of particular
identifying information of the second channel transmitted from the
first calling party to the called party through the network
interface means of the first calling party and the first
channel;
call control processing means for preparing, at the first calling
party or at the second calling party, the call transmitted to the
called party;
for adding, at the first calling party, the piece of particular
identifying information of the second channel to the call in cases
where the call is prepared at the first calling party;
for adding, at the second calling party, the piece of general
identifying information of the second channel to the call in cases
where the call is prepared at the second calling party;
for receiving, at the called party, the call prepared at the first
calling party or at the second calling party through the second
channel and the network interface means of the called party;
for disconnecting the call in cases where a release of the second
channel is notified; and
for establishing the call in cases where an establishment of the
call is notified;
incoming-call judging means for comparing, at the called party, a
received piece of identifying information of the second channel
added to the call received by the call control processing means of
the called party with the particular identifying information stored
in the identifying information controlling means of the called
party; and
for judging, at the called party, whether or not the received piece
of identifying information received by the call control processing
means of the called party agrees with the particular identifying
information stored in the identifying information controlling means
of the called party;
incoming-call judgement controlling means for notifying the call
control processing means of the called party of the release of the
second channel in cases where the incoming-call judging means of
the called party judges that the received piece of identifying
information does not agree with the particular identifying
information stored in the identifying information controlling means
of the called party; and
for notifying the call control processing means of the called party
of the establishment of the call at the called party in cases where
the incoming call judging means judges that the received piece of
identifying information agrees with the particular identifying
information stored in the identifying information controlling means
of the called party; and
information communicating means for transmitting, at the first
calling party, one or more pieces of visual information to the
called party through the network interface means and the first and
second channels in cases where the call control processing means
establishes the call transmitted through the second channel and
for receiving, at the called party, the visual information from the
first calling party through the network interface means and the
first and second channels to perform a visual communication between
the first calling party and the called party.
2. A visual communication terminal apparatus according to claim 1,
wherein the information communicating means comprises:
codec means for coding, at the first calling party, an image signal
and an audio signal indicating the visual information to produce a
coded image signal and a coded audio signal, and
for decoding, at the called party, the coded image signal and the
coded audio signal to reproduce the image signal and the audio
signal; and
multiplexing/demultiplexing means for multiplexing the coded image
signal and the coded audio signal produced by the codec means at
the first calling party to transmit multiplexed coded image and
audio signals to the called party through the network interface
means and the first and second channels, and
for demultiplexing, at the called party, the multiplexed coded
image and audio signals transmitted from the first calling party
through the network interface means and the first and second
channels, the demultiplexed coded image and audio signals being
decoded by the codec means.
3. A visual communication terminal apparatus according to claim 1,
wherein the identifying information controlling means
comprises:
bit-rate allocation signal controlling means for storing, at both
the first calling party and the called party, a plurality of pieces
of identifying information of a plurality of available channels in
a bit-rate allocation signal code area in bit-rate allocation
signal code form; and
identifying information interchange controlling means for reading,
at the first calling party, a piece of identifying information of
the second channel selected from among the available channels from
the bit-rate allocation signal controlling means as the particular
identifying information of the second channel;
for reading, at the called party, a piece of called-identifying
information of the second channel selected from among the available
channels from the bit-rate allocation signal controlling means;
for storing, at the called party, the particular identifying
information transmitted from the first calling party to the called
party through the network interface means and the first channel;
and
for storing, at the first calling party, the called-identifying
information transmitted from the called party to the first calling
party through the network interface means and the first
channel.
4. A visual communication terminal apparatus according to claim 1
wherein the identifying information controlling means
comprises:
bit-rate allocation signal controlling means for storing, at both
the first calling party and the called party, a plurality of pieces
of identifying information of a plurality of available channels and
the number of available channels in a bit-rate allocation signal
code area in bit-rate allocation signal code form; and
identifying information interchange controlling means for reading,
at the first calling party, a piece of identifying information of
the second channel selected from among the available channels from
the bit-rate allocation signal controlling means as the particular
identifying information of the second channel;
for reading, at the called party, a piece of called-identifying
information of the second channel selected from among the available
channels from the bit-rate allocation signal controlling means;
for storing, at the called party, the particular identifying
information transmitted from the first calling party to the called
party through the network interface means and the first channel;
and
for storing, at the first calling party, the called-identifying
information transmitted from the called party to the first calling
party through the network interface means and the first
channel.
5. A visual communication terminal apparatus according to claim 1
wherein the particular identifying information prepared by the
identifying information controlling means at the first calling
party is a particular telephone number of the second channel.
6. A visual communication terminal apparatus for communicating
between a first calling party and a called party connected through
a first channel, comprising at each called and calling party:
network interface means for transmitting at a first calling party,
to the called party through the first channel, a piece of
particular identifying information of a second channel differing
from the first channel;
for receiving, at the called party, the piece of particular
identifying information of the second channel transmitted from the
first calling party through the first channel;
for transmitting, at the called party, a particular telephone
number of the second channel to the first calling party through the
first channel;
for receiving, at the first calling party, the particular telephone
number of the second channel transmitted from the called party
through the first channel;
for transmitting, at the first calling party or at a second calling
party, a call to the called party according to the particular
telephone number of the second channel through the second channel;
and
for receiving, at the called party, the call transmitted from the
first calling party or the second calling party through the second
channel;
identifying information controlling means for preparing, at the
called party, the particular telephone number transmitted to the
first calling party through the network interface means;
for preparing, at the first calling party, the piece of particular
identifying information transmitted to the called party through the
network interface means of the first calling party and the first
channel;
for preparing, at the second calling party, a piece of general
identifying information of the second channel for transmission to
the called party through the network interface means of the second
calling party;
for storing, at the first calling party, the particular telephone
number transmitted from the called party to the first calling party
through the network interface means and the first channel; and
for storing, at the called party, the piece of particular
identifying information transmitted from the first calling party to
the called party through the network interface means of the first
calling party and the first channel;
call control processing means for preparing, at the first calling
party or at the second calling party, the call transmitted to the
called party;
for adding, at the first calling party, the piece of particular
identifying information of the second channel to the call in cases
where the call is prepared at the first calling party;
for adding, at the second calling party, the piece of general
identifying information of the second channel to the call in cases
where the call is prepared at the second calling party;
for receiving, at the called party, the call prepared at the first
calling party or at the second calling party through the second
channel and the network interface means of the called party;
for disconnecting the call in cases where a release of the second
channel is notified; and
for establishing the call in cases where an establishment of the
call is notified;
incoming-call judging means for comparing, at the called party, a
received piece of identifying information of the call received by
the call control processing means of the called party with the
particular identifying information stored in the identifying
information controlling means of the called party; and
for judging, at the called party, whether or not the received piece
of identifying information of the call received by the call control
processing means of the called party agrees with the particular
identifying information stored in the identifying information
controlling means of the called party;
incoming-call judgement controlling means for notifying the call
control processing means of the called party of the release of the
second channel in cases where the incoming-call judging means of
the called party judges that the received piece of identifying
information of the call received by the call control processing
means of the called party does not agree with the particular
identifying information stored in the identifying information
controlling means of the called party; and
for notifying the call control processing means of the called party
of the establishment of the call at the called party in cases where
the incoming call judging means judges that the received piece of
identifying information of the call received by the call control
processing means of the called party agrees with the particular
identifying information stored in the identifying information
controlling means of the called party; and
information communicating means for transmitting, at the first
calling party, one or more pieces of visual information to the
called party through the network interface means and the first and
second channels in cases where the call control processing means
establishes the call transmitted through the second channel and
for receiving, at the called party, the visual information from the
first calling party through the network interface means and the
first and second channels to perform a visual communication between
the first calling party and the called party.
7. A visual communication terminal apparatus according to claim 6,
wherein the information communicating means comprises:
codec means for coding, at the first calling party, an image signal
and an audio signal indicating the visual information to produce a
coded image signal and a coded audio signal, and
for decoding, at the called party, the coded image signal and the
coded audio signal to reproduce the image signal and the audio
signal; and
multiplexing/demultiplexing means for multiplexing the coded image
signal and the coded audio signal produced by the codec means at
the first calling party to transmit multiplexed coded image and
audio signals to the called party through the network interface
means and the first and second channels, and
for demultiplexing, at the called party, the multiplexed coded
image and audio signals transmitted from the first calling party
through the network interface means and the first and second
channels, the demultiplexed coded image and audio signals being
decoded by the codec means.
8. A visual communication terminal apparatus according to claim 6,
wherein the identifying information controlling means
comprises:
bit-rate allocation signal controlling means for storing, at the
first calling party, a plurality of pieces of identifying
information of a plurality of available channels in a bit-rate
allocation signal code area in bit-rate allocation signal code
form;
for storing, at the called party, a plurality of telephone numbers
of the available channels in a bit-rate allocation signal code area
in bit-rate allocation signal code form; and
identifying information interchange controlling means for reading,
at the first calling party, a piece of identifying information of
the second channel selected from among the available channels from
the bit-rate allocation signal controlling means as the particular
identifying information of the second channel;
for reading, at the called party, a telephone number of the second
channel selected from among the available channels from the
bit-rate allocation signal controlling means as the particular
telephone number of the second channel;
for storing, at the called party, the particular identifying
information transmitted from the first calling party to the called
party through the network interface means and the first channel;
and
for storing, at the first calling party, the particular telephone
number transmitted from the called party to the first calling party
through the network interface means and the first channel.
9. A visual communication terminal apparatus according to claim 6
wherein the identifying information controlling means
comprises:
bit-rate allocation signal controlling means for storing, at the
first calling party, a plurality of pieces of identifying
information of a plurality of available channels and the number of
identifying information in a bit-rate allocation signal code area
in bit-rate allocation signal code form;
for storing, at the called party, a plurality of telephone numbers
of the available channels and the number of telephone numbers in a
bit-rate allocation signal code area in bit-rate allocation signal
code form; and
identifying information interchange controlling means for reading,
at the first calling party, a piece of identifying information of
the second channel selected from among the available channels from
the bit-rate allocation signal controlling means as the particular
identifying information of the second channel;
for reading, at the called party, a telephone number of the second
channel selected from among the available channels from the
bit-rate allocation signal controlling means as the particular
telephone number of the second channel;
for storing, at the called party, the particular identifying
information transmitted from the first calling party to the called
party through the network interface means and the first channel;
and
for storing, at the first calling party, the particular telephone
number transmitted from the called party to the first calling party
through the network interface means and the first channel.
10. A visual communication terminal apparatus according to claim 6
wherein the particular identifying information prepared by the
identifying information controlling means at the first calling
party is a particular calling-telephone number of the second
channel.
11. A visual communication terminal apparatus for communicating
between a first calling party and a called party connected through
a first channel, comprising at each called and calling party:
network interface means for transmitting, at the first calling
party or at a second calling party, a call to the called party
through a second channel differing from the first channel; and
for receiving, at the called party, the call transmitted from the
first calling party or the second calling party through the second
channel;
call control processing means for preparing, at the first calling
party or at the second calling party, the call transmitted to the
called party;
for receiving, at the called party, the call prepared at the first
calling party or at the second calling party through the second
channel and the network interface means of the called party;
for disconnecting the call in cases where a release of the second
channel is notified; and
for establishing the call in cases where an establishment of the
call is notified;
incoming-call judging means for judging, at the called party,
whether or not the call received by the call control processing
means of the called party is prepared by the first calling
party;
incoming-call judgement controlling means for notifying the call
control processing means of the called party of the release of the
second channel in cases where the incoming-call judging means of
the called party judges that the call received by the call control
processing means of the called party is not prepared by the first
calling party; and
for notifying the call control processing means of the called party
of the establishment of the call at the called party in cases where
the incoming call judging means judges that the call received by
the call control processing means of the called party is prepared
by the first calling party; and
information communicating means for transmitting, at the first
calling party, one or more pieces of visual information to the
called party through the network interface means and the first and
second channels in cases where the call control processing means
establishes the call transmitted through the second channel and
for receiving, at the called party, the visual information from the
first calling party through the network interface means and the
first and second channels to perform a visual communication between
the first calling party and the called party.
12. A visual communication terminal apparatus according to claim
11, wherein the information communicating means comprises:
codec means for coding, at the first calling party, an image signal
and an audio signal indicating the visual information to produce a
coded image signal and a coded audio signal, and
for decoding, at the called party, the coded image signal and the
coded audio signal to reproduce the image signal and the audio
signal; and
multiplexing/demultiplexing means for multiplexing the coded image
signal and the coded audio signal produced by the codec means at
the first calling party to transmit multiplexed coded image and
audio signals to the called party through the network interface
means and the first and second channels, and
for demultiplexing, at the called party, the multiplexed coded
image and audio signals transmitted from the first calling party
through the network interface means and the first and second
channels, the demultiplexed coded image and audio signals being
decoded by the codec means.
13. A visual communication terminal apparatus for communicating
between a calling party and a called party connected thereto
through a first channel comprising, at each of said called party
and said calling party:
network interface means;
call control processing means;
incoming-call judging means;
incoming-call judgement controlling means; and
information communicating means, wherein:
said network interface means of said calling party operates for
transmitting a further call to said called party connected thereto,
through a second channel differing from said first channel; and
said network interface means of said called party operates for
receiving, through said second channel, the further call from the
calling party;
said call control processing means of said called party operates
for disconnecting a received call in response to notification to
release said second channel; and
said call control processing means of said called party further
operates for establishing a received call through said second
channel in response to notification to establish the call;
said incoming-call judging means of said called party operates for
judging whether or not a call received by said network interface
means of said called party through said second channel is said
further call transmitted by said calling party;
said incoming-call judgement controlling means of said called party
operates for notifying said call control processing means of said
called party to release said second channel in response to judgment
by said incoming-call judging means of said called party that the
call received by said network interface means of said called party
through said second channel is not said further call transmitted by
said calling party; and
said incoming-call judgement controlling means of said called party
further operates for notifying said call control processing means
of said called party to establish the received call on said second
channel in response to judgment by said incoming call judging means
of said called party that the call received by said network
interface means of said called party through said second channel is
said further call transmitted by said calling party;
said information communicating means of said calling party operates
for transmitting one or more pieces of visual information to said
called party through said network interface means of said calling
party and through said first and second channels in response to
establishment of the call through said second channel by said call
control processing means of said called party; and
said information communicating means of said calling party operates
for receiving said one or more pieces of visual information from
said calling party through said network interface means of said
called party and through said first and second channels to perform
a visual communication between said calling party and the called
party.
14. A visual communication terminal apparatus according to claim
13, wherein:
said network interface means of said calling party further operates
for transmitting to said called party, through said first channel,
a piece of particular identifying information of said second
channel;
said network interface means of said called party operates for
receiving the piece of particular identifying information of said
second channel transmitted from said calling party through said
first channel; and
further comprising, at each called and calling party, identifying
information controlling means;
said identifying information controlling means of said called party
operating for storing, at said called party, the piece of
particular identifying information of said second channel
transmitted from said calling party to said called party through
said first channel;
wherein said incoming-call judging means of said called party
judges whether or not a call received by the call control
processing means of the called party is the further call
transmitted from said calling party by comparing a received piece
of identifying information of the second channel in the received
call with the piece of particular identifying information of the
second channel stored in said identifying information controlling
means of said called party; and
by judging that the received call is the further call transmitted
by said calling party when the received piece of identifying
information included in the received call agrees with the piece of
particular identifying information stored in said identifying
information controlling means of said called party.
15. A visual communication performing method for communicating
between a first calling party and a called party connected through
a first channel, comprising the steps of:
transmitting, from the first calling party to the called party
through the first channel, a piece of particular identifying
information of a second channel differing from the first
channel;
transmitting to the called party through the second channel a call
from the first calling party including the piece of particular
identifying information or a call from a second calling party
including a piece of general identifying information;
judging whether or not received identifying information of the call
transmitted to the called party through the second channel agrees
with the piece of particular identifying information transmitted
from the first calling party through the first channel;
releasing the second channel to disconnect the second channel
between the called party and the second calling party in cases
where the received identifying information does not agree with the
piece of particular identifying information;
establishing the call by connecting the second channel between the
called party and the first calling party in cases where the
received identifying information agrees with the piece of
particular identifying information; and
transmitting one or more pieces of visual information from the
first calling party to the called party to perform a visual
communication between the first calling party and the called party
through the first and second channels in cases where the call is
established.
Description
BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention relates to a visual communication terminal (namely,
an image terminal or a video terminal) having a function of
performing a multiplex transmission of images (namely, still and
moving images), sound, audio, text or the like by using
communication circuits.
2. Description of the Related Art
When conventional visual communication terminals communicate
information generated by using multimedia including images, sound,
audio, text or the like, a user of one of the terminals (hereunder
sometimes referred to as a calling terminal) first sets a telephone
number of the other terminal (hereunder sometimes referred to as a
called terminal) in a keying portion of the calling terminal by
keying the number. Thereafter, when a telephone-number transmission
key is pushed, a call control processing portion of the calling
terminal performs an operation of connecting the calling and called
terminal with a communication circuit through a network interface
portion. Then, what is called a communication rate (namely, a
communication speed or transmission speed) of sound information is
inputted from the keying portion according to the CCITT
(Consultative Committee for International Telephone and Telegraph)
Recommendation H. 221. Further, the allocation of communication
circuits to channels, as well as the frame structure of each of
information signals representing sound information, image
information and character information, is determined according to
the inputted communication rate. Next, according to the BAS
(Bit-rate Allocation Signals) code of the CCITT Recommendation H.
241, the frame structure used in and the capability of each
terminal are interchanged between the calling and called terminals
and moreover, the communication mode of communication therebetween
is indicated.
In case where the conventional visual communication terminals
communicate with each other by using a plurality of communication
circuits, the aforesaid process is repeatedly performed plural
times, the number of which is equal to that of the communication
circuits. Thus, the conventional visual communication terminals are
connected with the communication circuits and communicate
information generated by using multimedia which includes images,
sound, audio, text or the like (namely, perform what is called
multimedia communications).
Further, for example, in the Japanese Unexamined Patent Publication
(Kokai Tokkyo Koho) Official Gazette No. H4-96562, there has been
proposed a conventional method. Namely, in case of this
conventional method, when a call originated from a calling terminal
is established on a first circuit connected between the calling
terminal and a called terminal, the called terminal transmits a
telephone number thereof corresponding to another available circuit
(namely, a second circuit) connected thereto, on which no call is
established, to the calling terminal by using the first circuit.
Then, when the calling terminal receives the telephone number
corresponding to the second circuit, the calling terminal
automatically dials the received telephone number to thereby
establish a call on the second circuit between the calling and
called terminals (namely, between calling and called parties).
SUMMARY OF THE INVENTION
It is an object of the present invention to provide a visual
communication terminal, connected to a plurality of circuits, which
terminal can judge whether or not a plurality of incoming calls are
originated from a same calling terminal (namely, a same calling
party), to thereby establish a plurality of calls between a user
thereof and an intended party.
To achieve the foregoing object, and in accordance with an aspect
of the present invention, there is provided a visual communication
terminal which comprises a network interface portion for
controlling communications through communication lines, a call
control processing portion for controlling a call through the
network interface portion, a telephone-number interchange control
portion for interchanging with a destination visual communication
terminal a telephone number, by which the destination visual
communication terminal can be communicated therewith through the
call control processing portion, and for storing a telephone number
of the destination visual communication terminal, by which the
destination visual communication terminal can be communicated
therewith, an incoming-call judgment portion for judging from the
telephone number stored in the telephone-number interchange control
portion and a calling-party number of a call set-up message newly
received through the call control processing portion whether or not
a calling party whose call has been established on a first channel
is the same as a calling party whose call is received from a second
channel later, a multiplexing/demultiplexing portion for
multiplexing an image signal and an audio signal, for transmitting
the multiplexed signals through the network interface portion and
for separating multiplexed signals received from the network
interface portion into an image signal and an audio signal and a
codec (namely, a code and encoder) portion for encoding image
information and audio information, for transmitting a generated
code to the multiplexing/demultiplexing portion, for decoding image
and audio signals received from the multiplexing/demultiplexing
portion and for generating an image and a sound.
With the aforementioned configuration, after a call is established
on a first channel, the visual communication terminal of the
present invention checks the communicating capability of a
destination visual communication terminal which also checks the
communicating capability of the visual communication terminal of
the present invention. If each of the communication terminals can
communicate by using a plurality of channels, the communication
terminals interchange telephone numbers, by which communications
therebetween can be realized, with each other and store the
interchanged telephone numbers. Then, the visual communication
terminal of the present invention judges from the telephone number
interchanged through a first channel or circuit and a calling-party
number of a call set-up message newly received through a second
channel or circuit whether or not a calling party whose call has
been established on the first channel is the same as a calling
party whose call is received from the second channel later (namely,
whether or not the telephone number of the calling party whose call
is received through the second channel later is the same as one of
the telephone numbers interchanged with the destination visual
communication terminal). Thereby, even in case where the visual
communication terminal of the present invention receives incoming
calls serially from a plurality of channels in case of
communicating with other visual communication terminals by using
the plurality of channels, the visual communication terminal of the
present invention can judge whether or not an incoming call is sent
from the same calling party as the calling party of the call
established on the first channel.
BRIEF DESCRIPTION OF THE DRAWINGS
Other features, objects and advantages of the present invention
will become apparent from the following description of a preferred
embodiment with reference to the drawings in which like reference
characters designate like or corresponding parts throughout several
views, and in which:
FIG. 1 is a schematic block diagram for illustrating the
configuration of a visual communication terminal embodying the
present invention (namely, the embodiment of the present
invention);
FIG. 2 is a diagram for illustrating an example of the frame format
of a signal representing an image, sound, audio, text, drawing or
the like, which format is based on the CCITT Recommendation and is
employed by the embodiment of the present invention;
FIG. 3 is a diagram for illustrating a sequence of steps of a
process of connecting communication circuits between visual
communication terminals embodying the present invention;
FIG. 4 is a diagram for illustrating an example of a set of
codewords of an extended BAS code to be used for interchanging
telephone numbers between visual communication terminals embodying
the present invention; and
FIG. 5 is a flowchart of a program for performing an operation of
connecting communication circuits between visual communication
terminals embodying the present invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
Hereinafter, a visual communication terminal embodying the present
invention (namely, the preferred embodiment of the present
invention) will be described in detail by referring to the
accompanying drawings.
FIG. 1 is a schematic block diagram for illustrating the
configuration of the visual communication terminal embodying the
present invention. In this figure, reference numeral 1 designates a
camera for taking a picture; 2 a microphone for inputting a voice;
3 a loudspeaker for outputting a voice; 4 a tablet for inputting
handwritten characters and drawings; 5 a keying portion for
inputting a telephone number and for selecting a function; 6 a
monitor display (hereunder sometimes referred to simply as a
monitor) for displaying an image to be sent therefrom and another
image sent from a destination visual communication terminal; 7 a
codec portion for performing a compression coding to convert image
information inputted from the camera 1 and audio information
inputted from the microphone 2 according to a predetermined coding
method into an image signal and an audio signal at an indicated
communication rate, for performing an expansion decoding on coded
image and audio signals which are received from another visual
communication terminal, and for outputting an image obtained as the
result of the decoding to the monitor 6 and also outputting an
obtained voice to the loudspeaker 3; 8 a telewriting control
portion for converting input information sent from the tablet 4,
which represents handwritten characters and drawings, into signals
to display the characters and drawings on the screen of the monitor
6; 9 a terminal control portion for controlling the terminal
according to input data inputted from the keying portion 5; 10 a
display control portion for changing or controlling the displaying
of an image on the screen of the monitor 6 according to
instructions or commands from the terminal control portion 9; 11 a
multiplexing/demultiplexing portion for multiplexing image, audio,
text and drawing signals according to the frame format of the CCITT
Recommendation H.221 (regarding a frame structure of signals
transmitted on a channel at at a transmission rate within the range
from 64 kilo-bits/second to 1920 kilo-bits/second (kbit/s), which
is employed in audio-visual teleservice as illustrated in FIG. 2)
and for separating a reception signal multiplexed according to the
CCITT Recommendation H.221 into signals representing an image,
audio, text and drawing or the like; 12 a BAS control portion for
performing a communication procedure based on the CCITT
Recommendation H. 242 (regarding a method for setting a
communication between digital audio-visual terminals using digital
channels, the transmission rates of which are up to 1920 kbit/s);
13 a telephone-number interchange control portion for inserting the
telephone number into an extended BAS code obtained by uniquely
defining a BAS code area which is not defined according to the
CCITT Recommendation, for reading an available telephone number
from the extended BAS code, for interchanging available telephone
numbers with other terminals and for storing the available
telephone numbers; 14 an incoming call judgement portion for
comparing the telephone number, which is stored in the
telephone-number interchange control portion after a first call is
established on a circuit or channel, with a calling-party number of
a call set-up message received through another circuit; 15 a call
control processing portion for managing call terminating,
originating and disconnecting or the like; 16 an incoming-call
judgment control portion for detecting a result of the comparison
made in the incoming-call judgement portion 14 and for notifying
the call control processing portion 15, if not matched, to transmit
a circuit release completion message indicating that a circuit or
line is released; 17 a system control portion for managing the
entire system; 18 a network interface portion for controlling a
connection with a communication circuit or line of an integrated
services digital network (ISDN) and a communication with the ISDN;
and 19 the ISDN.
Hereinafter, an operation of the visual communication terminal
embodying the present invention will be described in detail by
referring to the drawings.
FIG. 3 is a diagram for illustrating a sequence of steps of a
process of connecting communication circuits between visual
communication terminals embodying the present invention. The
sequence of steps of the process of connecting communication
circuits is performed according to the CCITT Recommendation. In
this figure, characters A, B and C denote a first calling party, a
second calling party and a called party, respectively. In the
following description, each of parts of the visual communication
terminal of the calling party A is indicated by adding character A
to the right side of corresponding reference numeral. Similarly,
each of parts of the visual communication terminal of the called
party C is indicated by adding character C to the right side of
corresponding reference numeral. Further, in the following
description, it is assumed that there are three communication
circuits or lines which can be used for making a communication
between the calling party A and the called party C.
First, the calling party A inputs predetermined information
representing a destination telephone number, a selected
communication function and the like, which are necessary for a call
origination, from the keying portion 5A. The information inputted
by the calling party A is then notified of through the terminal
control portion 9A to the call control processing portion 15A.
Subsequently, the call control processing portion 15A generates a
call set-up message containing predetermined information which
represents the destination telephone number, a kind of a
communication signals (for example, telephone, image or data
communication) and the like. Further, the call control processing
portion 15A transmits the generated call set-up message to the ISDN
19 through the system control portion 17A and the network interface
portion 18A. When receiving the call set-up message, the ISDN 19
notifies the visual communication terminal used by the called party
C of the call set-up message (see 1). Further, the ISDN 19 notifies
the visual communication terminal used by the calling party A of a
call set-up acceptance message indicating that the call set-up
message is surely received (see 2). Then, the call control
processing portion 15C of the called party C analyzes the received
call set-up message into the telephone number of the calling party
and the kind of the communication and the like. If a communication
can be made between the calling and called parties by using the
destination telephone number, the visual communication terminal of
the called party C transmits through the ISDN 19 to the visual
communication terminal of the calling party A a response message
indicating that a communication is permitted (see 3). When
receiving the response message, the call control processing portion
15A of the calling party A transmits through the ISDN 19 to the
visual communication terminal of the called party C a response
acknowledgment message indicating that the response message is
received by the calling party A (see 4). At that time, the call
control processing portion 15A of the calling party A analyzes the
received response message and thus knows whether or not a
communication is allowed by the visual communication terminal of
the called party C. If permitted, a call is established on a first
channel. Thereafter, the first channel is available for making a
communication therebetween.
When a call is established on the first channel, the BAS control
portions 12A and 12C of the visual communication terminals of the
calling and called parties check the functions and communication
capabilities of each other. If both of the visual communication
terminals can communicate with each other by using a plurality of
channels, the BAS control portions 12A and 12C and the
telephone-number interchange control portions 13A and 13C set the
telephone numbers corresponding to the predetermined plurality of
channels in the BAS code extended as illustrated in FIG. 4 and
interchange the telephone numbers with each other. Further, the
telephone-number interchange control portion 13A stores the
available telephone numbers of the called party C and on the other
hand, the telephone-number interchange control portion 13C stores
the available telephone numbers of the calling party A.
Here, an example of a set of codewords of the extended BAS code to
be used for interchanging the telephone numbers will be described
with reference to FIG. 4. FIG. 4 is a diagram for illustrating the
example of a set of codewords of the extended BAS code to be used
for interchanging the telephone numbers therebetween. As
illustrated in this figure, the high-order three bits (110) of a
first byte indicate that this code is an extended BAS code.
Further, the low-order three bits of the first byte represent the
number of additional circuits which are available for a
communication therebetween. In case that additional two circuits
corresponding to the telephone numbers 092-411-1112 and
092-411-1113 are available as in this case, the low-order three
bits are (010). Thus, for example, the bits (11011010) are coded as
the first byte. Next, the telephone number 092-411-1112 is divided
from the highest numeral every two digits into five two-digit
decimal numbers 09, 24, 11, 11 and 12. Further, each of these
decimal numbers is coded or represented by using eight bits
(incidentally, the high order four bits represent a high order
digit of each of the decimal numbers and the low order four bits
represent a low order digit of each of the decimal numbers) as
(00001001), (00100100), (00010001), (00010001) and (00010010).
Subsequently, the byte coded as (11110000) is used as a delimiter.
Next, similarly, the other telephone number 092-411-1113 is divided
from the highest numeral every two digits into five two-digit
decimal numbers. Further, each of these decimal numbers is coded or
represented by using eight bits, similarly as in case of the
telephone number 092-411-1112. Thus (00001001), (00100100),
(00010001), (00010001) and (00010011) are obtained. Subsequently,
the byte coded as (11110000) is similarly used as a delimiter.
When receiving a next incoming call (namely, a second incoming
call), the call control processing portion 15C of the visual
communication terminal of the called party C analyzes a call set-up
message received at that time and notifies the incoming call
judgment portion 14C of the telephone number of a calling party
(see 5of FIG. 3). Subsequently, the ISDN 19 notifies the visual
communication terminal used by the calling party of a call set-up
acceptance message indicating that the call set-up message is
surely received by the visual communication terminal of the called
party (see 6). Then, the incoming-call judgment portion 14C
compares the telephone number of the calling party notified of from
the call control processing portion 15C with each of the
destination telephone numbers stored in the telephone-number
interchange control portion 13C. If matched, the incoming-call
judgment portion 14C regards this incoming call as an incoming call
sent from an intended called party and moreover transmits through
the call control processing portion 15C to the destination visual
communication terminal (namely, in this case, the visual
communication terminal of the calling party A) a response message
indicating that the visual communication terminal of the called
party permits the terminal of the calling party to communicate
therewith (see 7). Then, the call control processing portion 15A of
the visual communication terminal of the calling party A analyzes
the response message and detects the permission to communicate with
the visual communication terminal of the called party C. Moreover,
the call control processing portion transmits through the ISDN 19
to the visual communication terminal of the called party C a
response acknowledgement message indicating that the response
message is surely received (see 8). Thus, a call is established on
a second channel. Thereafter, the second channel is available for
making a communication therebetween.
When receiving a third incoming call subsequent to the second
incoming call, the call control processing portion 18C of the
visual communication terminal of the called party C analyzes a call
set-up message received this time and notifies the incoming call
judgment portion 14C of the telephone number of a calling party
(see 9). Then, the ISDN 19 notifies the visual communication
terminal used by the calling party of a call set-up acceptance
message indicating that the call set-up message is securely
received by the visual communication party of the called party (see
10). Subsequently, the incoming-call judgment portion 14C compares
the telephone number of the calling party notified of from the call
control processing portion 15C with each of the destination
telephone numbers stored in the telephone-number interchange
control portion 13C. If it is detected that there is no match, the
incoming-call judgment portion 14C regards this incoming call as an
incoming call sent from a party (in this case, the calling party B)
other than the intended called party and moreover transmits through
tile call control processing portion 15C to the destination visual
communication terminal (namely, in this case, the visual
communication terminal of the calling party B) a release completion
message and disconnects this call from the visual communication
terminal of the called party (see 11). At that time, the call
control processing portion 15C may disregard the call sent from the
visual communication terminal of the calling party B.
Thereafter, when receiving still another incoming call (namely, a
fourth incoming call) subsequent to the third incoming call, the
call control processing portion 15C of the visual communication
terminal of the called party C analyzes a call set-up message
received this time and notifies the incoming call judgment portion
14C of the telephone number of a calling party (see 12 of FIG. 3).
Subsequently, the ISDN 19 notifies the visual communication
terminal used by the calling party of a call set-up acceptance
message indicating that this call set-up message is surely received
by the visual communication terminal of the called party (see 13).
Then, the incoming-call judgment portion 14C compares the telephone
number of the calling party notified of from the call control
processing portion 15C with each of the destination telephone
numbers stored in the telephone-number interchange control portion
13C. If matched, the incoming-call judgment portion 14C regards
this incoming call as an incoming call sent from an intended called
party and further transmits through the call control processing
portion 15C to the destination visual communication terminal
(namely, in this case, the visual communication terminal of the
calling party A) a response message indicating that the visual
communication terminal of the called party allows the terminal of
the calling party to communicate therewith (see 14). Then, the call
control processing portion 15A of the visual communication terminal
of the calling party A analyzes the response message and detects
the permission to communicate with the visual communication
terminal of the called party C. Furthermore, the call control
processing portion 15A transmits through the ISDN 19 to the visual
communication terminal of the called party C a response
acknowledgement message indicating that the response message is
surely received (see 15). Thus, this call is established on a third
channel. Consequently, the calls, the number of which is equal to
that of the available channels (or circuits) interchanged through
the first channel, are established. Thereafter, the channels of
such a number are available for making communications therebetween.
As the result of performing the aforesaid procedure, a plurality of
calls from a same calling party are established on a plurality of
channels. Further, the visual communication terminals communicate
with each other by using a plurality of channels.
Hereinafter, the operation of the visual communication terminal
embodying the present invention will be further described in detail
by referring to the flowchart of the program for performing the
operation. FIG. 5 is a flowchart of a program for performing the
operation of connecting communication circuits (or lines) between
visual communication terminals embodying the present invention.
Incidentally, the sequence of steps for connecting communication
circuits (or lines) therebetween are performed on the basis of the
CCITT Recommendation.
Namely, in step S1, the visual communication terminal awaits a
first incoming call. If there is an incoming call, the program
advances to step S2. Then, in step S2, the terminal of the called
party analyzes a call set-up message and judges whether or not the
visual communication terminal of the calling party has a capability
of communicating with the visual communication terminal of the
called party. If the terminal of the calling party has such a
capability, the program advances to step S3. In contrast, if not,
the program advances to step S10. In step S3, the call is
established and each of the visual communication terminals
respectively corresponding to the calling and called parties checks
the functions and communication capabilities of the other terminal.
If each of the visual communication terminals respectively
corresponding to the calling and called parties can communicate by
using a plurality of channels, these terminals interchange
predetermined plurality of telephone numbers preliminarily set in
each of the terminals with each other. Then, the program goes
forward to step S4 whereupon it is judged whether or not a
communication can be made by using a plurality of channels. If
possible, the program advances to step S5 through Y-branch. If a
communication is made by a single channel, the program advances to
step S9 through N-branch. Meanwhile, in step S5, the visual
communication terminal of the called party awaits a next incoming
call. If there is the next incoming call (namely, a second incoming
call), the program advances to step S6 whereupon the visual
communication terminal of the called party analyzes a call set-up
message received this time and compares a telephone number
indicated by this call set-up message with each of the telephone
numbers checked and interchanged in step S3. If matched, the
program goes to step S7 through Y-branch. In contrast, if not
matched, the program advances to step S11 through N-branch. In step
S7, the terminal establishes this call. Subsequently, the program
goes forward to step S8 whereupon it is judged whether or not a
call is established on each of the circuits (or lines)
corresponding to the telephone numbers checked and interchanged in
step S3. If, among these circuits, there is a circuit on which no
call is established, the program goes back to step S5. In contrast,
if calls are established on all of the circuits corresponding to
the telephone numbers checked and interchanged in step S3, the
program advances to step S9 whereupon the visual communication
terminals commence a communication therebetween.
Meanwhile, in step S10, the visual communication terminal of the
called party transmits a release completion message to the calling
party. Thereby, the visual communication terminal of the called
party rejects the incoming call sent from the calling party. Then,
the program goes back to step 1. Similarly, in step S11, the visual
communication terminal of the called party transmits a release
completion message to the calling party to thereby reject the
incoming call sent from the calling party. Then, the program goes
back to step 5. As the result of performing the aforementioned
process according to the flowchart of FIG. 5, calls issued from the
same calling party are established on a plurality of channels.
Consequently, the visual communication terminals of the present
invention communicate with each other by using the plurality of
channels.
While the preferred embodiment of the present invention has been
described above, other various embodiments of the present invention
may be made without changing the spirit or essential
characteristics thereof. The foregoing description of the preferred
embodiment of the present invention is, accordingly, for
illustrative purposes only. Thus it is to be understood that the
present invention is not limited thereto. The scope of the present
invention, therefore, is to be determined by the appended claims
rather than the description preceding them. All changes and
modifications covered by the appended claims fall within the scope
of the present invention.
* * * * *